Package for preparation and dispensing of heated foam

ABSTRACT

A package adapted for preparing and dispensing heated foam, which comprises a manually openable sealed outer container and a manually rupturable sealed inner container, said package containing A. an aqueous dispersion of a foamable composition, B. hydrogen peroxide, C. a reductant composition, D. an organic propellant selected from A. 1,2-Dichlorohexafluoropropane B. 1,2-Dichloro-1,2,2-trifluoroethane C. Perfluorodimethylcyclobutane D. 1,2-Dichloroperfluorocyclobutane WHEREIN MATERIALS (B) and (C) are isolated from each other in the separate containers of said package.

United States Patent [151 3,638,786 Borecki et al. 1 Feb. 1, 1972 [541PACKAGE FOR PREPARATION AND 3,372,839 3/1968 Hayes ..222/94 DISPENSING0F HEATED FOAM FOREIGN PATENTS OR APPLICATIONS [72] Inventors: WilliamJoseph Borecld; Frederick John Gradlshnr, both of Wilmington, Del.l'll0'557 4/1968 [73] Assignee: E. l. du Pont de Nemours and Company,Primary Examiner-Herbert B. Guynn Great Britain Wilmington, Del.Attorney-Francis J. Crowley [22] Filed: Nov. 12, 1969 [57] ABSTRACT [2118759649 A package adapted for preparing and dispensing heated foam,

which comprises a manually openable sealed outer container 52 us. Cl...206/47 A, 252/90, 252/305, and a manually Immutable sealed containerSaid 424/45, 424/47 Package wmining [51] lnt.Cl. ..C09k3/30,A61k7/l4 Aana queous dispersion of a foamable composition. [58] Field of Search..252/90, 186, 305, 424/47, 45, hydrogen peroxide 206/47 229/35 MF C. areductant composition,

D. an organic propellant selected from [561 Rehm Cited a.1,Z-Dichlorohexafluoropropane b. l ,2-Dichloro-1,2,2-trifluoroethane c.Perfluorodimethylcyclobutane d. l,2-Dichloroperfluorocyclobutane whereinmaterials. B and C are isolated from each other in thsii etw ms l m Saidsma UNITED STATES PATENTS 3,354,088 11/1967 Elmquist ..252/90 5aimsTDrIflving Figiii'e's' f 17.17.7 7.22. I II I 1 I 1 'f-\ I 2- i l 21 II I j 3 E I 1 1.52:1; l

PATENTED FEB 1 1972 FIG.!

INVENTORS WILLIAM JOSEPH BORECKI FREDERICK JOHN GRADISHAR BY ATTORNEY IPACKAGE FOR PREPARATION AND DISPENSING OF HEATED FOAM BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates to a packageadapted for preparing and dispensing self-heating foam in which heat isgenerated by a redox reaction and in which a normally liquid propellantis utilized.

2. Description of Prior Art The field of heated foam packages ispredominated by rigid, complex and costly containers and dispenserscontaining therein foamable compositions, redox reactants and variouspropellants. Such packages normally provide for separate storage ofoxidants and reductants, with one of these reactants combined duringstorage with the foamable composition. Mechanical valves, passages,tubes and the like provide the means for mixing of oxidant, reductantand foamable composition upon expulsion from the container.

A package has now been invented which allows for the preparation anddispensing of heated foam from noncomplex, nonrigid containers whichemploy normally liquid propellants.

SUMMARY OF THE INVENTION The present invention comprises a packagehaving a manually openable scaled outer container and a manuallyrupturable sealed inner container, said package containing A. an aqueousdispersion of a foamable composition,

B. hydrogen peroxide C. a reductant composition which reacts at roomtemperature with the said hydrogen peroxide to produce heat, saidreductant composition being an alkali metal sulfite or a mixture of analkali metal sulfite and an alkali metal thiosulfate,

and t D. an organic propellant for dispensing material (A) selected froma. 1,2-Dichlorohexafluoropropane b. l ,Z-Dichlorol ,2,2-trifluoroethanec. Perfluorodimethylcyclobutane d. l,2-Dichloroperfluorocyclobutanewherein materials (B) and (C) are isolated from each other in theseparate containers of said package.

DESCRIPTION OF THE DRAWINGS FIG. I is a top view of a package of thisinvention.

FIG. 2 is a cross section of the package of FIG. 1 along the lines 2-2.cDESCRIPTION OF THE INVENTION It is now been discovered that heatedfoams can be prepared and dispensed from noncomplex, nonrigid containersemploying therein a normally liquid propellant heated to a temperatureabove its boiling point by redox reaction. The complexity and cost ofthe prior art containers comprises rigid walls, mechanical valves,passages, etc., are thus avoided.

The package of this invention in its preferred embodiment, as shown inFIGS. 1 and 2, intended for single use, comprises a manually openableouter container I prepared from a plastic or plastic laminated on itsoutside to metal foil which container is sealed 5 and contains afoamable material and a reductant or reductants 2 selected from analkali metal sulfite alone or in a mixture with an alkali materialthiosulfate. Within this outer container is a smaller manuallyrupturable inner container 3 which is sealed 6 and contains hydrogenperoxide 4 in an amount chemically equivalent to or preferably slightlyless than equivalent to the amount of reductant contained in the mixturewith the foamable material. The hydrogen peroxide may be optionallythickened as described in the examples. Thickened hydrogen peroxide,while producing more stable foams, is however more difficult to mix.Other embodiments are of course possible, e.g., the containers could beprepared from flexible molded plastic provided that the inner containeris still rupturable.

It is readily apparent also that the order of storage of the reactantsmay be reversed, that is, the hydrogen peroxide may be contained in theouter container and the other materials in the inner container. Further,as taught by Seglin et al., in French Pat. No. 1,468,909, the hydrogenperoxide may be stored in mixture with selected soaps which do notdecompose the hydrogen peroxide. The reductants are, of course, storedin a container separate from the hydrogen peroxide container within thepackage thus isolating the two reactants from each other while instorage.

It will occur to one skilled in the art that various materials can beused to prepare the containers of the package of this invention. Aprimary consideration, however, is that the material of the hydrogenperoxide containing container not catalytically decompose hydrogenperoxide, nor should the hydrogen peroxide attack or rapidly permeatethe container material. The material of construction of the nonhydrogenperoxide containing container is less critical. Polyethylene, forexample, is a suitable material and if the nonhydrogen peroxidecontaining container is the outer container, polyethylene laminated to astronger film such as polyethylene terephthalate may be used.

In utilizing one embodiment of this invention, the inner sealedcontainer is first ruptured manually, e.g., by the application ofpressure between the fingers; the package is then shaken to allow thereactants to contact one another thus effecting the heat generatingredox reaction; the outer sealed container is then manually opened,e.g., by puncturing or tearing off a corner, and the heated foamextrudes from the package through the opening thus created.

The term aqueous dispersion of a foamable composition" referred toherein means an aqueous solution or dispersion of a foam-producing agentcapable of forming a foam when dispensed from the package of thisinvention. There are no special limitations on the nature of thefoamable composition except that it should not contain any materialswhich would interfere with the redox reaction, e.g., it should notcontain oxidants which would oxidize the sulfite or thiosulfatereductant dissolved therein. Strongly acid materials which would alterthe reductants are also undesirable. Strongly alkaline materials can,however, be utilized for they do in fact accelerate the redox reaction.These strongly alkaline materials may be particularly effective whenutilized as oven cleaners and the like. Materials which stronglycatalyze the decomposition of hydrogen peroxide, such as those describedin Seglin et al., French Pat. No. 1,468,909, are avoided because theheat produced by hydrogen peroxide decomposition is less than thatproduced by redox reaction on an equal weight basis. The best type andconcentration of foam-producing agent in the composition for aparticular application can be readily deter-- mined by one skilled inthe art and is not critical for purposes of this invention; however, thecomposition usually contains about 30 to 35 percent by weight offoam-producing agent. Useful foam-producing agents are exemplified bythe soluble anionic soaps, for example the potassium, ammonium andsoluble amine soaps of stearic acid, as well as vegetable oils soaps,various synthetic materials known as wetting agents or surfactants andfibrous alumina monohydrate in combination with a foam coactive. Thefoamable composition should be nongelling at room temperature, andcontain additives known in the art such as glycerine, light mineral oil,perfume, antifreeze agents, silicon fluids, viscosity controlling agentsand the like. Products to be applied to the body, such as shavinglathers, hair conditioners, etc., must, of course, contain onlyphysiologically acceptable materials and the pH must be near Thereductants of this invention react with hydrogen peroxide at roomtemperature, e.g., alkali metal sulfites or a mixture of an alkali metalsulfite and alkali metal thiosulfate. The preferred reductants arepotassium sulfite and a mixture of potassium sulfite and potassiumthiosulfate because there is less likelihood that the potassium saltswill gel soap solutions. In the case of a mixture of the sulfite andthiosulfate salts, the

mol ratio of potassium thiosulfate to potassium sulfite is not critical;however, for best results the ratio should be from about 3 to 5 to about2 to 3, respectively. Furthermore, for best results, the amount ofreductant mixture present in admixture with the aqueous dispersion of afoamable composition, if in fact they are admixed, while not critical,usually ranges from about 6 to 10 percent by weight. When the reductantutilized is potassium sulfite salt alone and it is admixed with theaqueous dispersion of a foamable composition, the amount of saidreductant in admixture is usually from about 6 to 10 percent.

Several physical properties appear to affect the suitability of anormally liquid propellant for use in this invention. The most importantof these properties appears to be the boiling point of the propellant,and the choice of propellant based on boiling point properties isaffected by the temperature at which the package is to be heated. in thesystem of this invention, this temperature is fixed by the amounts ofoxidant and reductant, the choice of reductant, the heat capacity of thematerials of package construction, the heat loss from the package andthe latent heat of vaporization of the propellant. A comfortabletemperature for application of foam to the human skin is from about 120to about 150 F.

The overall stability of the heated foams produced appears to be relatedto less clearly defined physical properties such as the ability of thepropellant to disperse in the foamable composition. The stability of thefoam appears to be related not only to its composition as known in theart but also to the permeation rate of the propellant through the cellwalls, condensation of the propellant within the cells upon cooling ofthe foam, etc.

it has been found that chlorofluorocarbons and perfluorocarbons havingboiling points of from about 80 to about 1 F. are suitable propellantsfor use in'this invention. While propellants having boiling points abovethis range, i.e., to about 140 F., are sometimes operable. The rangedescribed above is preferred and the most preferred boiling point isabout 95 F. The following normally liquid propellants, arranged in theorder of decreasing preference, are effective when utilized in thepresent invention.

Boiling Point Propellant F.

l,2-dichlorohexafluoropropane 94.] l,2-dichlorol ,2,2-trifluoroethane82.8 Perlluorodimethylcyclobutane I 14.0 (mixed isomers)l,Z-dichloroperfluorocyclobutane I393 About 12 to 18 percent ofpropellant is usually used based on the combined weight of propellantand foamable composition. The amount of propellant utilized may,however, be greater depending upon the containers used.

EXAMPLES PART A Formu- Formu- Formulation l lation 2 lation 3 wt. '35wt. 96 wt.

Acetylated lanolin 0.8 0.8 0.8 Cetyl alcohol 0.5 0.5 0.5 Sorbitolmonostearatc 0.5 0.5 0.5 Mineral oil 0.5 0.5 0.5 Polyoxycthylenesorbitnn 4.5 4.5 4.5 monostearate' PART B Formu- Formu- F0rmulation llation 2 lation 3 wt. wt. wt. Coconut fatty acid L0 L0 Stearic acid 9.07.0 7.0 Stearyl Alcohol 1.0 Laurie Acid l.0

PART C Formu- Formu- Formulation l lation 2 lation 3 wt. 35 wt. wt. 1.

Deionized Water 66.l 69.! 68.] Triethanolamine 3.5 3.5 3.5 PotassiumHydroxide L2 L2 L2 Potassium Sulfite '2H,O 5.0 5.0 9.0 PotassiumThiosulfatc 3.0 3.0 Sorbitol, 70 wt. 96 in Water 3.0 3.0 3.0 Perfume 0.40.6 0.4

Modulam" American Cholesterol Products Co., Edison. NJ.

Arlacel 60, Atlas Chemical Industries, Wilmington, Del.

"Tween" 60, Atlas Chemical Industries, Wilmington. Del.

"Sorbo" 70, Atlas Chemical Industries, Wilmington, Del.

The hydrogen peroxide solutions were prepared by dilution with deionizedwater of commercial concentrated hydrogen peroxide containingconventional inhibitors. The thickened hydrogen peroxide formulationscontaining 13 wt. percent hydrogen peroxide were prepared as follows:

ingredient Wt. Hydrogen peroxide, 35 wt. 37.0 Cetyl alcohol 2.5 Glycerolmonostearate 2.5 Deionized water 58.0

The deionized water at 70 C. was slowly stirred into a 70 C. meltedmixture of cetyl alcohol and glycerol monostearate. The mixture wasallowed to cool while stirring whereupon 35 percent hydrogen peroxidewas added with stirring until blended. Deionized water was then added tomake up evaporation losses.

The outer container used in the examples consisted of two approximately3%X4 in. sheets of 10 mil thick polyethylene laminated on the outside toaluminum foil. The inner con tainer, containing hydrogen peroxide,consisted of two pieces of approximately 1 mil thick polyethylene sheetabout I in. square.

EXAMPLE l In the runs reported in Table l of this example, the hydrogenperoxide was charged to the inner container which was then heat sealedand placed inside the outer container. The soap formulations andpropellant were added to the outer container which was then also heatsealed. In these runs, the sealed containers were first shakenvigorously, the inner container was then ruptured and the contents ofboth envelopes were mixed by kneading for about 30 seconds whereupon acorner of the outer container was torn off. The warm foam was expressedinto a beaker where its temperature was measured by a small thermometerin the center of the foam.

The results of the 12 runs are shown in Table 1 below.

TABLE 1 Outer container Max. Run Soap lormulatemp. No. Inner container,H202 tion Propellant F.) Foam appearance I 1 cc. wt. percent H 5 g. N o.3"... 0.6 cc. 1,Z-dlchlorohexafluoropropane. 105 Wet, flowing. IL. 2 cc.13 wt. percent H202 8 g. No. 2. 1 0 cc. 1,2-dlchlorohexafluoropropane120 Large bubbles. III 2 (1)3 wt. percent thickened 8 g. N o. 2. (10-.122 Bubbles smaller than Ex. 2.

2 2. H 2 cc. 13 wt. percent H202 8 g. No. 1 d0 126 Good shave lather. Vdc 8 g. No. 1 1.0 cc. 1,l,2-trlchloro-l,2,2-trlfluoroethane. 132 Soulike foam, collapsed at once. VI- ..do.. 8 g. No. 1..... 1.0 cc.1,2-dlchloro-1,2,2-trifluoroethane. 131 Su sy lather. VIL. ..do 8 g. No.1..- 1.0 cc. perfluorodimethylcyclobutane 142 Very large bubblescollapsed. VIII- do 8 g. No. 1. 1.0 cc. 1,2-dichloroperfluorocyelobutane135 Wet foam, collpased. IX 2 (1)3 wt. percent thickened 8 g. No. 1 do132 No foam. 2 2- d 8 g. No. 1 1.0 cc. perfluorodlmethylcyclobutane 129Creamy liquid.

8 g. No. 1... 1.0 cc. 1,Z-dichlorohexafluoropropane-- 138 Dry foam. 8 g.No. 2 ..do 130 v oluminous moist foam.

Since heated foams are needed for various applications, all thoseformulations above which produced foams of some stability are regardedas operable. Propellants which in at least one formulation producedfoams of some stability are therefore also regarded as operable.

It should be noted that when l,l,2-trichloro-l,2,2- trifluoroethane wasutilized as the propellant in Run No. V, the results wereunsatisfactory; and yet when 1,2-dichlorohexafluoropropane of thisinvention was utilized as the propellant with the same formulation (RunNo. IV), the results were quite satisfactory.

For shave lather the components of runs IV and Xll are preferred.

EXAMPLE 2 In another embodiment of this invention, a redox reaction ofhydrogen peroxide and sodium sulfite was carried out separately in anintermediate container, the heat of reaction therefrom being transferredthrough the wall of the intermediate container to warm the soap solutioncontained in the outermost container.

The package therefore consisted of three containers, one inside theother. The innermost polyethylene container, approximately 1 inchsquare, contained 0.4 cc. of 30 weight percent H 0 and 2.6 cc. water andwas heat sealed at the edges. The intermediate container, about 2X3inches in size and consisting of 4 mil polyethylene, contained 0.4 gramssodium sulfite and was sealed at the edges. The outer containercontaining 5 cc. of an approximately 24 percent aqueous solution ofcommercial lather shave cream and 2 cc. l,2-dichloro-l,2,2-trifluorocthane, consisted -of a 2 mil thick, 1 qt. capacitypolyethylene bag heat sealed at all edges. Air was excluded from allenvelopes before heat sealing.

The innermost container was ruptured and its contents were mixed withthe sodium sulfite of the intermediate container by kneading. Thepackage was then shaken and warmed foam was expressed from the outermostcontainer, through an opening which was made therein, into a graduatedfunnel. Approximately 80 cc. of foam was realized which was stable formore than 20 minutes.

The novel package of this invention has a variety of applications whereit is desired to prepare and dispense warm aqueous foam. The inventionis especially useful for preparing areas of a person to be shaved, andwashing the skin or hair. Such utility is particularly beneficial tocampers, yachtsmen and others who often do not have access to hot water.This novel package is adapted for preparing warm foam quickly,efficiently and without a need for a source of electricity, steam, orhot water.

Although the chemical components of this invention have been describedin the examples in terms of potassium and sodium salts, it is evidentthat any alkali metal sulfite or a mixture of any alkali metal sulfiteand thiosulfate would be operable. it is further understood that as manyapparently widely different embodiments of this invention may be madewithout departing from the spirit and scope thereof, the invention isnot limited to the specific embodiments thereof.

What we claim is:

l. A package adapted for preparing and dispensing heated foam, whichcomprises a manually openable sealed outer container and a manuallyrupturable sealed inner container, said package containing A. an aqueousdispersion of a foamable composition selected from the group consistingof soluble anionic soaps,

8. hydrogen peroxide,

C. a reductant composition which reacts at room temperature with thesaid hydrogen peroxide to produce heat, said reductant composition beingan alkali metal sulflte or a mixture of an alkali metal sulfite and analkali metal thiosulfate, and

D. an organic propellant for dispensing material (A) selected from thegroup consisting of a. l,2-Dichlorohexafluoropropane and b.1.2-Dichloro-l ,2,2-trifluoroethane wherein materials (B) and (C) areisolated from each other in the separate containers of said package.

2. A package according to claim 1 wherein the organic propellant (D) isl,2-dichlorohexafluoropropane.

3. A package according to claim 1 wherein the organic propellant (D) is1,2-dichloro-l ,2,2-trifluoroethane.

4. A package according to claim 1 wherein the outer container isprepared from polyethylene laminated on the outside to aluminum foil.

5. A package according to claim 1 wherein the inner container isprepared from polyethylene.

i #8 t l t

2. A package according to claim 1 wherein the organic propellant (D) is1,2-dichlorohexafluoropropane.
 3. A package according to claim 1 whereinthe organic propellant (D) is 1,2-dichloro-1,2,2-trifluoroethane.
 4. Apackage according to claim 1 wherein the outer container is preparedfrom polyethylene laminated on the outside to aluminum foil.
 5. Apackage according to claim 1 wherein the inner container is preparedfrom polyethylene.